Combination gas and electric hotwater heater with heat absorber-transmitter in the flue



v. R. ROSTEK 2, COMBINATION GAS AND ELECTRI HOT-WATER HEATER Feb. 17,1953 C WITH HEAT ABSORBER-TRANSMITTER IN THE FLUE Filed April 7, 1951HUI 'IIIIIIIIII l-I'IIIIIIIIIIII.

v INVENTOR. aw 15/2 I ATTOHVEY Patented Feb. 17, 1953 COMBINATION GASAND ELECTRIC HOT- WA'IER HEATER WITH HEAT ABSORBER- TRANSIVIITTER. INTHE FLUE Vincent Rudolf vRostek, Philadelphia, .Pa.

Application April 7, 1951, Serial No. 219,801

My invention relates to a new and useful combination gas and electrichot water heater with heat absorber-transmitter in the flue and has forone of its objects to provide a household boiler of the upright typewith simple, eflicient, strong and durable means for absorbing a portionof the heat generated during the water heating periods and reradiatesome of the absorbed and stored heat to a portion of the boiler andthence to the water for maintaining the water in a heated condition fora longer time than would ordinarily be the case.

Another object of the invention is to produce a heat exchangerconsisting of a tubular casing to be suspended in a central flue of aboiler and containing sand or an equivalent heat absorbing substance.

Another object of this invention is to mount a plurality of baffles onthe sand holding casing in suitable spaced relation longitudinally ofsaid casing and, preferably, said baffles increasing in size in fixedratio from the bottom to the top of said casing whereby their edges arein an inverted conical plane.

Another object of the present invention is to provide means forsuspending the sand holding casing within the central flue, saidsuspending means or hanger comprising either a strap of anycross-sectional shape or a tubular piece having its interior incommunication with the interior of said casing, said suspendng means orhanger being connected to either the upper head of the boiler or theinlet and outlet in any appropriate manner.

A further object of the invention is to provide a vent in the side ofthe sand holding casing to permit breathing of said casing due totemperature fluctuations therein.

A still further object of this invention is to produce a casingsuspending means or hanger from a tubular section welded or otherwisesecured to the normally closed upper end of the sand holding casing andhaving the interiors of said hanger and casing in communication for aircirculation and said hanger further provided with a valved vent whichmay be utilized for filling the casing with sand.

Also, a highly desirable advantage of the present invention is that itreduces to a minimum the likelihood of condensation during periodsbetween heating operations which often results in rustng or corrosion ofthe boiler elements that might finally cause leaky conditions.

With the above and other objects in view this invention consists of thedetails of construction 5 Claims. (01. 12217) and combination ofelements hereinafter set forth and then designated by the claims.

In .order that those skilled in the art to which this inventionappertains may understand how to make and use the same, I will describeits construction in detail, referring by numerals to the accompanyingdrawing forming a part hereof, in which:

Fig. 1 a longitudinal sectional view of an upright boiler, with someparts left in elevation, showing my improved heat exchanger assembled inthe central flue and suspended by one type of hanger.

Fig. 2 is a fragmentary top plan and sectional view on the line 22 ofFig. 1.

Fig. .3 is an elongated sectional view of the central flue and heatexchanger therein on the line 3-3 of Fig. 1.

Fig. 4 is a fragmentary and broken perspective view of another type ofhanger.

Fig, 5 .is also a fragmentary view, in section, of the type of hanger inFig. 4 and the sand holding casing, in the region of the joint betweensaid elements.

In carrying out my invention as herein embodied l0 represents a hotwater boiler, generally known as a vertical or upright household boilerbut .can be employed anywhere desired for providing a supply of hotwater. lhe water in this type of boiler is usually heated by a singleheating unit, the fuel for which may be gas, electricity or oil, but Iprefer to employ two heating units, one of them being of the flameburning type, supplied either by gas or oil, and the other of theelectric heating type.

For purposes of illustration, the heating element 1 I is of the flameburning type and the heating element I2 is any well known electric waterheating device. Either one can be used according to the desires of theuser or should one become inoperative the other can be temporarily usedas a substitute. Also, when it is desirable to obtain hot water veryquickly both heating elements can be operated simultaneously.

The boiler may be mounted on feet 13 or equivalent supporting means andhas a water inlet nipple leading to the interior for supplying coldwater to the bolier and an outlet nipple I5 leading from said boiler tolocations of use.

In the boiler is a central flue I6 open at both the lower and upper endsfor the passage of air entering the lower end as it is heated by theheating .unit I l and flowing from the upper end through the short pipeI! of the cap 18, mounted on the upper projecting end of said flue, theair then traveling to a stack in the usual manner, which stack isconnected to the upper end of the cap and a chimney.

The central flue I6 is connected at its lower end to the dome shapedbottom wall IQ of the tank portion of the boiler and projects throughand a short distance above the upper head 20. In this central flue I6 isassembled the heat exchanger 2l, preferably in the upper portion of saidflue, as shown in Fig. 1. The heat exchanger 2| includes a tubularcasing 22 of any desirable cross sectional shape and is closed at thelower end, as by a pipe cap 23, and is also completely closed at itsupper end, Figs. 1 and 2, as by a pipe cap 24 or substantially closed atsaid upper end, Figs. 4 and 5, as by a pipe cap 24a having a hole 24btherethrough. The tubular casing 22 contains dry sand 25, or otherequivalent heat absorbent material, Fig. 3, and has a vent opening 26,Figs. 1 and 3, in the side thereof adjacent the upper end.

The heat exchanger is, preferably, suspended in the upper portion of thecentral flue by a suitable suspension means and as illustrated in Figs.1 and 2 the suspension means is in the form of a hanger strap 21 securedto the pipe cap 24 by any appropriate means, such as by welding 28. Theends of the suspension hanger strap are attached to any desirable partof the upper portion of the boiler, such as the upper head thereof orthe inlet and outlet nipples and, merely for purposes of illustration,said hanger strap is depicted as fastened to said inlet and outletnipples l4 and I5, respectively, by clamps 29 of any suitable formation.

The suspension means is shown in Figs. 4 and 5 as including a hollow ortubular hanger limb 21a secured to the top end of the upper pipe cap240: by suitable means, such as by welding 28a and the ends of saidhanger limb are attached to any suitable part of the upper portion ofthe boiler as described in connection with the hanger strap. Ifdesirable, clamps 29a of appropriate construction may be provided at theends of said hanger limb.

A hole 30 is formed in the under side of the hanger limb and is inregistration with the hole 241; so said holes provide a passageway tofunction as a vent and communication between the interiors of the sandholding casing and hanger limb for circulation of air from one to theother. Diametrically opposite the hole 30 is formed another hole 3|,preferably slightly larger than said hole 30 to permit unobstructed flowof sand or other equivalent material in comminuted form therethrough forsubsequent passage through the holes 30 and 2411 into the chamber of thecasing 22. A plug 32 is inserted in the hole 3| when the latter is notin use for filling the casing with a heat absorbing material and saidplug has a small vent opening 33 through it which may be controlled by avalve 34, Fig. 5, if such is desired, to allow the escape of expandingair Without permitting the ingress of cold air.

Regardless of the type of suspension means utilized and the specifictype and arrangement of vent, a plurality of fins or bafiies 35 of anydesirable or appropriate shape are mounted on the exterior of the casingin longitudinally spaced relation and increasing in size from the bottomone to the top one whereby their outer edges are in the plane of aninverted cone or pyramid as indicated by the dot and dash lines 36 inFig. 1.

In practice, the flame from the heating unit II will impinge on thebottom wall Hi to raise the temperature of the water within the boilerand also raise the temperature of the air in and flowing through thecentral flue l6 to further raise the temperature of the water. The finsor baflies retard the flow of hot air through the central flue anddirect its course towards the flue walls for absorption of some of theheat by the water and towards the casing 22 to heat the latter and itscontents. Thereafter, when the heating unit is temporarily shut off, asby an automatic control, the heat stored by the heat exchanger willgradually be transferred from the casing to the air in the central flueand thence to the water in the boiler retaining the temperature of saidwater at a relatively high degree for a considerable period of time.When the electric heating unit I2 is employed separately some of theheat in the water will be transferred to the air in the central flue andthence to the heat exchanger for subsequent reverse action.

While the plain hanger strap illustrated in Figs. 1 and 2 functions in ahighly eflicient manner I have found that by using the hollow hangerlimb slightly better results are obtained because the air in the hangerlimb chamber becomes heated and assists in retaining the heat exchanger,as a whole, at a relatively high temperature for a longer period oftime.

As the heat exchanger remains hot for a considerable length of timeafter the temperature of the water begins to fall, any moisture ladenair flowing through the central flue will be dried out so thatcondensation will be reduced to a mini mum thus helping to preventcorrosion.

Of course I do not wish to be limited to the exact details ofconstruction herein shown and described as these may be varied withinthe scope of the appended claims without departing from the spirit of myinvention.

Having described my invention what I claim as new and useful is:

1. In combination, an upright household boiler including inlet andoutlet nipples and having a central vertical flue open at both ends, theupper end of said flue projecting above the upper head of said boiler, aflame heating element below the lower end of said flue, an electricheating unit in the boiler, a heat exchanger assembled in said flue andincluding a tubular casing located in the longitudinal axis of saidflue, means to close the lower end of said casing, means tosubstantially close the upper end of said casing, said upper closuremeans having a hole therethrough, a tubular hanger limb havingdiametrically opposite aligned holes of difierent sizes thereinintermediate the ends thereof, said hanger limb secured to the upperclosure means with the smaller hole in alignment with the hole in theupper closure means, a plug having a small aperture therethrough andinserted in the larger hole and sand within the casing, and means toattach the ends of the hanger limb to portions of the boiler for holdingthe casing in suspension in the upper portion of the flue.

2. The structure according to claim 1, in combination with a valve tocontrol the flow of air outwardly through the aperture in the plug.

3. The structure according to claim 1, in combination with battles onthe exterior of the casing in spaced relation longitudinally of saidcasing, said baflles increasing in size in uniform order from the lowerone to the uppermost one.

4. In a device of the kind described, the combination with an uprighthousehold boiler having a central flue therein open at both ends, a heatexchanger positioned in the upper portion of said flue, said heatexchanger including a tubular casing closed at the lower end and havingan apertured cap on its upper end, a tubular limb fixedj 'to said capand having aligned diametrical openings in alignment with the aperturein the cap whereby the interior of the casing is in communication withthe interior and exterior of the limb, means to temporarily close thecommunication to the exterior, the ends of said limb having means tofasten it to supports for suspending the casing, dry sand containedwithin said casing, and thin flat shaped bafiies fixed on the outside ofthe casing in spaced relation longitudinally of said casing to deflect acurrent of hot air and cause it to follow a vertically circuitous pathof travel.

5. The structure according to claim 4 wherein the diameters of thebaflies increase in uniform order from the lower one to the upper one.

VINCENT RUDOLF ROSTEK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 904,627 Lovekin Nov. 24, 1908983,912 Lovekin Feb. 14, 1911 1,044,469 Allen Nov. 19, 1912 1,269,052Clark et a1. June 11, 1918 1,640,284 Mitchell Aug. 23, 1927 1,642,539Choinski Sept. 13, 1927 1,780,316 Schwartz Nov. 4, 1930 2,286,677 GrethJune 16, 1942 2,348,901 Handley 1- May 16, 1944 2,379,155 Hufi June 26,1945

